64 CULTIVATION METHODS AND ROTATIONS FOR GREAT PLAINS. 



be sown. If the field is to be sown to winter grain in the fall, the 

 treatment should be the same as the summer tillage up to the time 

 of seeding. 



If this rotation is adopted and the plowing under of the winter rye 

 is carefully done and the after-culture is sufficiently thorough, much 

 better results will undoubtedly be obtained than from the summer 

 tillage without the growing of a crop for turning under. The great 

 objection to summer tillage is the fact that it is very destructive to 

 the organic matter or humus in the soil, while this rotation will pre- 

 serve and even increase the organic matter in the soil. The cost of 

 seeding the field to rye is not great, and the labor involved is no more 

 than would be necessary for the summer tillage carried on as thor- 

 oughly as it should be. 



FOUR-YEAR ROTATION (NO. 5). 



Field A, 40 Acres. 



1910. Corn. 



1911. Wheat, winter or spring. 



1912. Field peas or cowpeas turned under 



in spring. 



1913. Oats, barley, emmer, or wheat. 



Field B, 40 Acres. 



1910. Wheat, winter or spring. 



1911. Field peas or cowpeas turned under 



in spring. 



1912. Oats, barley, emmer, or wheat. 



1913. Corn. 



Field C, 40 Acres. 



1910. Field peas or cowpeas turned under 



in spring. 



1911. Oats, barley, emmer, or wheat. 



1912. Corn. 



1913. Wheat, winter or spring. 



Field D, 40 Acres. 



1910. Oats, barley, emmer, or wheat. 



1911. Corn. 



1912. Wheat, winter or spring. 



1913. Field peas or cowpeas turned under 



in spring. 



Rotation No. 5 is exactly like rotation No. 4 except that field peas 

 or cowpeas will be used in the place of the winter rye. As both of 

 these crops have the power of gathering the free nitrogen from the 

 air and converting it into forms in which it can be used by succeeding 

 crops, they are preferable in this respect to winter rye. The prepa- 

 ration of the land during the fall after the wheat has been removed 

 should be the same as that recommended for fall plowing for other 

 crops. In the spring the field peas or cowpeas should be sown as 

 early as climatic conditions will permit. The time of seeding will, of 

 course, depend upon the locality, and the rate of seeding should 

 depend upon the fertility of the soil. As heavy a seeding should be 

 given as the soil is capable of developing, as it is desirable, of course, 

 to get as large an amount of growth for turning under as possible. 

 Some very favorable results have been obtained by substituting sweet 

 clover (Melilotus alba) for peas. When this is done, the sweet clover 

 should be sown with the wheat crop and plowed under the next sea- 

 son before any seeds have matured, as it becomes a very bad weed 

 in some localities. 



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